patch 8.0.0751: OpenPTY missing with some combination of features

Problem:    OpenPTY missing with some combination of features. (Kazunobu
            Kuriyama)
Solution:   Adjust #ifdef.  Also include pty.pro when needed.

Author: brammool

src/misc2.c

@@ -6050,6 +6050,9 @@ moreenv(void)
 }
 
 # ifdef USE_VIMPTY_GETENV
+/*
+ * Used for mch_getenv() for Mac.
+ */
     char_u *
 vimpty_getenv(const char_u *string)
 {

src/proto.h

@@ -212,15 +212,18 @@ void qsort(void *base, size_t elm_count, size_t elm_size, int (*cmp)(const void
 #  include "channel.pro"
 # endif
 
-# ifdef FEAT_GUI
-#  include "gui.pro"
+# if defined(FEAT_GUI) || defined(FEAT_JOB_CHANNEL)
 #  if defined(UNIX) || defined(MACOS)
 #   include "pty.pro"
 #  endif
+# endif
+
+# ifdef FEAT_GUI
+#  include "gui.pro"
 #  if !defined(HAVE_SETENV) && !defined(HAVE_PUTENV) && !defined(VMS)
-extern int putenv(const char *string);		/* from pty.c */
+extern int putenv(const char *string);			/* in misc2.c */
 #   ifdef USE_VIMPTY_GETENV
-extern char_u *vimpty_getenv(const char_u *string);	/* from pty.c */
+extern char_u *vimpty_getenv(const char_u *string);	/* in misc2.c */
 #   endif
 #  endif
 #  ifdef FEAT_GUI_W32

src/pty.c

@@ -43,7 +43,7 @@
 
 #include "vim.h"
 
-#if defined(FEAT_GUI) || defined(FEAT_TERMINAL)
+#if defined(FEAT_GUI) || defined(FEAT_JOB_CHANNEL)
 
 #include <signal.h>
 

src/version.c

@@ -769,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    751,
 /**/
     750,
 /**/